Data storage is an important problem in the field of computing. Many data storage technologies have been developed over the years, including solid state, optical, and magnetic storage techniques. Each technology has faced different challenges, but in general, developers of storage devices have attempted to increase data storage density, decrease access speed, and reduce costs as much as possible. Solid state storage devices generally provide rapid access to stored data, but are relatively expensive (per unit of data stored) when compared to magnetic or optical storage technologies. Magnetic disks are generally able to store more data than solid state memories at lower cost, while providing moderate access speeds. Magnetic tape is often used for archiving large amounts of data because it provides vast amounts of long term storage (due in part to the large surface area provided on a magnetic tape), albeit with a relatively slower access rate.